Tutorial: Create a Docker image for a Java application

A template project to create a Docker image for a Java application. The example application exposes an HTTP endpoint.

The Docker build uses a multi-stage build setup to minimize the size of the generated Docker image.

Golang developer? Check out https://github.com/miguno/golang-docker-build-tutorial

Requirements

Docker must be installed. That's it. You do not need a Java JDK or Maven installed.

Usage and Demo

Step 1: Create the Docker image according to Dockerfile. This step uses Maven to build, test, and package the Java application according to pom.xml. The resulting image is 87MB in size.

# This may take a few minutes.
$ docker build -t miguno/java-docker-build-tutorial:latest .

Step 2: Start a container for the Docker image.

$ docker run -p 8123:8123 miguno/java-docker-build-tutorial:latest

Step 3: Open another terminal and access the example API endpoint.

$ curl http://localhost:8123/status
{"status": "idle"}

Notes

You can also build, test, package, and run the Java application locally (without Docker) if you have JDK 8+ and Maven installed.

# Build, test, package the application locally
$ mvn package

# Run the application locally
$ java -jar target/app.jar